I don’t mean just things that you would never get to do, like having a sixsome with your five favorite celebrities. I mean things that are truly impossible by all anatomical, mechanical or physical laws, at least unless you were genetically engineered, a shape-shifter or a traveler to alternate universes.
Ok, my thread so I have to post an example: In some of my fantasies…I have an animal penis. By which I mean that instead of a normal human penis, I have a sheath out of which when I’m aroused sprouts a long, thick bright red phallus like an oversized dog cock. Not that I’m a furry; I’m a normal human except for my penis. Usually in these scenerios I’m in a fantasy forest world in which elves, fairies, dryads, assorted semi-humans and other female denizens of the forest find my equipment irresistable.